Radiographic Differentiation of Advanced Fibrocystic Lung Diseases

Clustered Cystic Changes in Long-Term Follow-Up Thin-Section Computed Tomographic Findings in Fibrotic Nonspecific Interstitial Pneumonia

Objectives

The purpose of this study was to retrospectively assess cystic changes in findings on follow-up CT scans of patients with fibrotic nonspecific interstitial pneumonia (NSIP).

Methods

The initial and last high-resolution CT scans of 58 patients with pathologically proven fibrotic NSIP were evaluated retrospectively. The median follow-up periods were 48 months (range, 12-183 months). The pattern, extent, and distribution of abnormal CT findings were compared with findings in the same region on previous and subsequent CT scans with a focus on cystic lesions.

Results

Cystic lesions in a cluster were shown in 16 patients (28%) with fibrotic NSIP on the last CT scans. Focal clustered cysts were found in 5 cases and diffuse clustered cysts were seen in 11 cases. Focal clustered cysts mimicked honeycombing seen in usual interstitial pneumonia (UIP). Diffuse cysts were uniform in size in 7 of the 11 cases. Traction bronchiectasis in a cluster was seen in 3 of the 7 cases. The clustered cystic changes on CT during the course of NSIP mainly consisted of traction bronchiectasis and bronchiolectasis.

Conclusions

Long-standing NSIP did not form honeycombing. The clustered cysts in patients with fibrotic NSIP were mainly remodeling of bronchiectasis.

Sarcoidosis Associated with Enlarged Mediastinal Lymph Nodes with the Detection of Streptococcus gordonii and Cutibacterium acnes Using a Clone Library Method

A 77-year-old Japanese woman with mediastinal lymphadenopathy and uveitis was diagnosed with sarcoidosis. The bacterial flora in biopsied samples from mediastinal lymph nodes was analyzed using a clone library method with Sanger sequencing of the 16S rRNA gene, and Streptococcus gordonii (52 of 71 clones) and Cutibacterium acnes (19 of 71 clones) were detected. No previous study has conducted a bacterial floral analysis using the Sanger method for the mediastinal lymph node in sarcoidosis, making this case report the first to document the presence of S. gordonii and C. acnes in the mediastinal lymph node of a patient with sarcoidosis.

The Importance of Imaging in the Assessment of Interstitial Lung Diseases

High-resolution computed tomography (HRCT) is an essential component of the diagnosis and assessment of patients with interstitial lung diseases (ILDs). In some cases, a diagnosis of ILD can be made solely based on a multidisciplinary discussion of HRCT findings and clinical evaluation. HRCT findings also inform prognosis and may influence treatment decisions. It is essential that high-quality HRCT images are obtained using parameters for optimum spatial resolution. Key terms used to describe HRCT findings should be used consistently among clinicians. Radiologic information should be included as part of the multidisciplinary discussion of patients with ILDs during follow-up.

Sarcoidosis-associated pulmonary fibrosis: joining the dots

Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology. A minority of patients with sarcoidosis develop sarcoidosis-associated pulmonary fibrosis (SAPF), which may become progressive. Genetic profiles differ between patients with progressive and self-limiting disease. The mechanisms of fibrosis in SAPF are not fully understood, but SAPF is likely a distinct clinicopathological entity, rather than a continuum of acute inflammatory sarcoidosis. Risk factors for the development of SAPF have been identified; however, at present, it is not possible to make a robust prediction of risk for an individual patient. The bulk of fibrotic abnormalities in SAPF are located in the upper and middle zones of the lungs. A greater extent of SAPF on imaging is associated with a worse prognosis. Patients with SAPF are typically treated with corticosteroids, second-line agents such as methotrexate or azathioprine, or third-line agents such as tumour necrosis factor inhibitors. The antifibrotic drug nintedanib is an approved treatment for slowing the decline in lung function in patients with progressive fibrosing interstitial lung diseases, but more evidence is needed to assess its efficacy in SAPF. The management of patients with SAPF should include the identification and treatment of complications such as bronchiectasis and pulmonary hypertension. Further research is needed into the mechanisms underlying SAPF and biomarkers that predict its clinical course.

Smoking-related interstitial lung disease

Exposure to smoke is associated with the development of diseases of the airways and lung parenchyma. Apart from chronic obstructive pulmonary disease (COPD), in some individuals, tobacco smoke can also trigger mechanisms of interstitial damage that result in various pathological changes and pulmonary fibrosis. A causal relation has been established between tobacco smoke and a group of entities that includes respiratory bronchiolitis-associated interstitial lung disease (RB-ILD), desquamative interstitial pneumonia (DIP), Langerhans cell histiocytosis (LCH), and acute eosinophilic pneumonia (AEP). Smoking is considered a risk factor for idiopathic pulmonary fibrosis (IPF); however, the role and impact of smoking in the development of this differentiated clinical entity, which has also been called combined pulmonary fibrosis and emphysema (CPFE) as well as nonspecific interstitial pneumonia (NIP), remains to be determined. The definition of smoking-related interstitial fibrosis (SRIF) is relatively recent, with differentiated histological characteristics. The likely interconnection between the mechanisms involved in inflammation and pulmonary fibrosis in all these processes often results in an overlapping of clinical, radiological, and histological features in the same patient that can sometimes lead to radiological patterns of interstitial lung disease that are impossible to classify. For this reason, a combined approach to diagnosis is recommendable. This combined approach should be based on the joint interpretation of the histological and radiological findings while taking the clinical context into consideration. This paper aims to describe the high-resolution computed tomography (HRCT) findings in this group of disease entities in correlation with the clinical manifestations and histological changes underlying the radiological pattern.

Syndrome of Combined Pulmonary Fibrosis and Emphysema: An Official ATS/ERS/JRS/ALAT Research Statement

Background: The presence of emphysema is relatively common in patients with fibrotic interstitial lung disease. This has been designated combined pulmonary fibrosis and emphysema (CPFE). The lack of consensus over definitions and diagnostic criteria has limited CPFE research. Goals: The objectives of this task force were to review the terminology, definition, characteristics, pathophysiology, and research priorities of CPFE and to explore whether CPFE is a syndrome. Methods: This research statement was developed by a committee including 19 pulmonologists, 5 radiologists, 3 pathologists, 2 methodologists, and 2 patient representatives. The final document was supported by a focused systematic review that identified and summarized all recent publications related to CPFE. Results: This task force identified that patients with CPFE are predominantly male, with a history of smoking, severe dyspnea, relatively preserved airflow rates and lung volumes on spirometry, severely impaired DlCO, exertional hypoxemia, frequent pulmonary hypertension, and a dismal prognosis. The committee proposes to identify CPFE as a syndrome, given the clustering of pulmonary fibrosis and emphysema, shared pathogenetic pathways, unique considerations related to disease progression, increased risk of complications (pulmonary hypertension, lung cancer, and/or mortality), and implications for clinical trial design. There are varying features of interstitial lung disease and emphysema in CPFE. The committee offers a research definition and classification criteria and proposes that studies on CPFE include a comprehensive description of radiologic and, when available, pathological patterns, including some recently described patterns such as smoking-related interstitial fibrosis. Conclusions: This statement delineates the syndrome of CPFE and highlights research priorities.

Combined Pulmonary Fibrosis and Emphysema and Digital Clubbing

Combined pulmonary fibrosis and emphysema (CPFE) is an underrecognized syndrome that involves simultaneous restrictive-obstructive lung disease. The prognosis is poor, and it frequently occurs with comorbidities. Heavy or former smoking is a major risk factor, and computed tomography (CT) typically shows lower zone fibrosis and upper zone emphysema. Chronic respiratory failure, pulmonary hypertension, and lung carcinoma are major causes of mortality. Diagnosis of CPFE should be combined with palliative care due to the high mortality of the condition, especially in the case of delayed diagnosis. We present the case of a 73-year-old male with a history of non-small cell lung cancer, 50 pack-year smoking, and cervical spine injury (CSI) with a late diagnosis of CPFE. After presenting to the emergency department for an acute exacerbation of dyspnea and hypoxia, he was initially treated with a congestive heart failure protocol. Further examination showed mixed pulmonary function tests as well as digital clubbing, and a CT scan showed changes indicative of advanced bullous emphysema diffusely throughout both lungs with an upper lobe predominance and basilar fibrosis. He was diagnosed with CPFE and immediately treated for both restrictive and obstructive lung diseases with supplemental oxygen, albuterol, ipratropium, corticosteroids, systemic antibiotics, as well as provided with palliative consultation. His previous history and CSI delayed diagnosis, as his lung restriction was likely assumed to be from impaired chest wall mobility rather than CPFE. This case highlights the presentation of a relatively rare disease that was confounded by comorbidities. 

Emerging Roles of Airway Epithelial Cells in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal disease with incompletely understood aetiology and limited treatment options. Traditionally, IPF was believed to be mainly caused by repetitive injuries to the alveolar epithelium. Several recent lines of evidence, however, suggest that IPF equally involves an aberrant airway epithelial response, which contributes significantly to disease development and progression. In this review, based on recent clinical, high-resolution imaging, genetic, and single-cell RNA sequencing data, we summarize alterations in airway structure, function, and cell type composition in IPF. We furthermore give a comprehensive overview on the genetic and mechanistic evidence pointing towards an essential role of airway epithelial cells in IPF pathogenesis and describe potentially implicated aberrant epithelial signalling pathways and regulation mechanisms in this context. The collected evidence argues for the investigation of possible therapeutic avenues targeting these processes, which thus represent important future directions of research.

Advanced pulmonary sarcoidosis

PURPOSE OF REVIEW

Mortality in patients with sarcoidosis has primarily been attributed to advanced pulmonary sarcoidosis. This review aims to provide an update on recent clinical studies that help to better phenotype these patients, discuss new treatment options, and suggest areas where additional research is needed.

RECENT FINDINGS

Diagnosis and management of advanced pulmonary sarcoidosis has changed as new technologies and treatment options have emerged. Clinical phenotypes of advanced disease have evolved to show overlap in presentation with other interstitial lung diseases. Assessment involves more advanced imaging modalities. New promising treatment options are being studied. Pulmonary rehabilitation and lung transplantation are being utilized to improve health-related quality of life and survival.

SUMMARY

Patients with advanced pulmonary fibrosis can have variable clinical, radiographic, histopathologic presentation. Given the poor health-related quality of life and high rates of mortality, medical therapy and pulmonary rehabilitation may benefit these patients. Lung transplantation should be considered in those with end-stage disease.

Topographic heterogeneity of lung microbiota in end-stage idiopathic pulmonary fibrosis: the Microbiome in Lung Explants-2 (MiLEs-2) study

BACKGROUND

Lung microbiota profiles in patients with early idiopathic pulmonary fibrosis (IPF) have been associated with disease progression; however, the topographic heterogeneity of lung microbiota and their roles in advanced IPF are unknown.

METHODS

We performed a retrospective, case-control study of explanted lung tissue obtained at the time of lung transplantation or rapid autopsy from patients with IPF and other chronic lung diseases (connective tissue disease-associated interstitial lung disease (CTD-ILD), cystic fibrosis (CF), COPD and donor lungs unsuitable for transplant from Center for Organ Recovery and Education (CORE)). We sampled subpleural tissue and airway-based specimens (bronchial washings and airway tissue) and quantified bacterial load and profiled communities by amplification and sequencing of the 16S rRNA gene.

FINDINGS

Explants from 62 patients with IPF, 15 patients with CTD-ILD, 20 patients with CF, 20 patients with COPD and 20 CORE patients were included. Airway-based samples had higher bacterial load compared with distal parenchymal tissue. IPF basilar tissue had much lower bacterial load compared with CF and CORE lungs (p<0.001). No microbial community differences were found between parenchymal tissue samples from different IPF lobes. Dirichlet multinomial models revealed an IPF cluster (29%) with distinct composition, high bacterial load and low alpha diversity, exhibiting higher odds for acute exacerbation or death.

INTERPRETATION

IPF explants had low biomass in the distal parenchyma of all three lobes with higher bacterial load in the airways. The discovery of a distinct subgroup of patients with IPF with higher bacterial load and worse clinical outcomes supports investigation of personalised medicine approaches for microbiome-targeted interventions.